Tribological Properties of UHMWPE Composites Filled with Nano-powder of SiO{sub}2 Sliding against Ti-6Al-4V

摘要

Wear is the primary cause of the failure of joint replacement prostheses. In this paper, the ultra-high molecular weight polyethylene (UHMWPE) as an artificial joint acetabular material was filled with nano-powder of SiO{sub}2 of various mass fractions. The effect of SiO{sub}2 mass fraction on the tensile strength, tensile modulus, wetting property and tribological properties of the SiO{sub}2-UHMWPE composites were investigated when sliding against Ti-6Al-4V under lubrication of physiological saline water. The morphologies of the worn surfaces of composites were observed with optical microscope. As a result, the tensile strength, tensile modulus, wettability and wear resistance of the composites were all improved by filling with SiO{sub}2, and the composites had largely decreased friction coefficients under lubrication of physiological saline water compared with the unfilled UHMWPE. This was attributed to the reinforcing function of the nano-powder of SiO{sub}2 in the composites and the lubricating action of the water boundary film. The wear of pure UHMWPE was dominated by plowing, plastic deformation, while the SiO{sub}2-UHMWPE was characterized the mild fatigue wear.